Communication devices have during the last decades evolved from being more or less primitive telephones, capable of conveying only narrow band analog signals such as voice conversations, into the multimedia mobile devices of today capable of processing large amounts of data representing any kind of data, including text data, as well as very complex multi media content and game data.
While the processing capability of these devices has increased, their physical sizes are typically very small. A problem related to such devices is then how to enable a user to conveniently input data via keys on a keypad to the processing circuitry of the device. For example, a typical telephone keypad comprises 12 keys arranged in a 3 by 4 matrix configuration, each key having a plurality of functions depending on which processing is performed. Such a keypad configuration is adequate for most purposes relating to telephone applications, such as dialing a telephone number and typing short text messages, but not adequate enough when a user desires to perform more complex typing operations, such as inputting long texts or controlling a game.
In the prior art, there are a number of different solutions to problems relating to keypad input in telephone devices. Among these are devices having a first keypad, having the typical 3 by 4 matrix configuration, sometimes located partly in front of a display and configured to be tilted away revealing a larger part of the display on which a second, virtual, keypad is presented.
One example of a dual keypad telephone is the Nokia 9110 communicator. The 9110-device comprises a main body having one large keypad and a so-called flip lid with a small keypad together with a small display on one side and a large display on the opposite side of the lid. In a first configuration, the lid is in a closed position, covering the main body keypad, and the phone is controlled by means of the small lid keypad. The lid can be tilted away from the main body, thereby placing the device in a second configuration where the main body keypad is revealed as well as the large display of the lid.
Another example in the prior art is that of the Nokia model 6800 mobile telephone. The 6800-device comprises a main body having one keypad and a so-called flip lid with two keypads on opposite sides of the lid. In a first configuration, the lid is in a closed position, covering the main body keypad, and the phone is controlled by means of one of the lid keypads. The lid can be tilted away from the main body, thereby placing the device in a second configuration where the second lid keypad is revealed as well as the main body keypad. In the second configuration, the display is interspaced between the main body keypad and the lid keypad.